Suture Anchor Biomechanics After Rotator Cuff Footprint Decortication

PURPOSE: To identify the biomechanical consequences of violating the cortical shelf when preparing the greater tuberosity for suture anchor repair. METHODS: Demographic information and bone mineral density were obtained for 20 fresh-frozen human humeri (10 matched pairs). Suture anchors were placed at a predetermined location in decorticated and non-decorticated settings after randomization. Anchors were tested under cyclic loads followed by load-to-failure testing. The number of cycles, failure mode, stiffness, and final pullout strength were recorded. RESULTS: Nineteen specimens met the inclusion criteria for final testing. A significant difference in mean ultimate load to failure was seen between the non-decorticated specimens (244.04 ± 89.06 N/mm) and the decorticated humeri (62.84 ± 38.04 N/mm, P < .0001). Regression analysis showed positive correlations with female gender and decreased bone mineral density (P = .008 and P = .0005, respectively). CONCLUSIONS: Decortication of the rotator cuff footprint significantly decreases the pullout strength of the suture anchor. Gender and bone mineral density also play a significant role in bone-anchor biomechanics and should be considered during repair. CLINICAL RELEVANCE: Caution should be exercised when preparing the rotator cuff footprint before suture anchor placement because of the significant risk of early repair failure at the bone-anchor interface.